<!DOCTYPE HTML>
<html>
<head></head>
<body>
	<script type="text/javascript">
		window.addEventListener('message', function(event) {
			var command = event.data.command;
			switch(command) {
				case 'eval':
					var ret = '';
					var success = true;
					try {
						ret = eval(event.data.content);
						console.log('ret', ret);
					} catch (err) {
						success = false;
					}
					event.source.postMessage({
						success: success,
						ret: ret
					}, event.origin);
					break;
			}
		});
	</script>
</body>
</html>